Quick: Clean up Mir2Lir codegen.

Clean up WrapPointer()/UnwrapPointer() and OpPcRelLoad().

Change-Id: I1a91f01e1e779599c77f3f6efcac2a6ad34629cf
diff --git a/compiler/dex/quick/arm64/call_arm64.cc b/compiler/dex/quick/arm64/call_arm64.cc
index 1dcbe60..823cb60 100644
--- a/compiler/dex/quick/arm64/call_arm64.cc
+++ b/compiler/dex/quick/arm64/call_arm64.cc
@@ -525,7 +525,7 @@
   // NOTE: Method deduplication takes linker patches into account, so we can just pass 0
   // as a placeholder for the offset.
   LIR* call = RawLIR(current_dalvik_offset_, kA64Bl1t, 0,
-                     target_method_idx, WrapPointer(const_cast<DexFile*>(target_dex_file)), type);
+                     target_method_idx, WrapPointer(target_dex_file), type);
   AppendLIR(call);
   call_method_insns_.push_back(call);
   return call;